At the end of the book he fakes his own death in Danzig (Hitler himself delivers the eulogy at his 'funeral') and stows away with his colleague, Alfred Reck, on a British cargo ship bound for Cardiff.
On their return to Britain he and Reck are faced with the problem of a series of unexplained sinkings of ships not long out of harbour in Portsmouth in They Tell No Tales (1941).
In Green Hazard (1945) the Gestapo mistake him for Professor Ulseth, inventor of a new and extremely powerful high explosive, and kidnap him.
In these later adventures, he is frequently aided by Forgan and Campbell, a semi-comic team of model-makers from the Clerkenwell Road in London, who first appear in A Brother for Hugh (1947).
[2] He eventually became the youngest officer in British intelligence, often working behind German lines, due to his extraordinary ability to master languages.